Socket adapter



Feb. 11', 1941.

F. c. DE REAMER EI'AL SOCKET ADAPTER Filed Feb. 25. 1939 Inventors: FranK ODeReamen Arthur W. Cl audefi ei r- Aot orney Patented Feb. 11, 1941' UNITED STATES PATENT OFFICE SOCKET ADAPTER I Application February 25, 1939, Serial No. 258,454

14 Claims.

This invention relates to socket adapters, and more particularly to a socket adapter for use with a projector or reflector type of incandescent lamp. 7

It is an object of the invention to provide an adapter for an incandescent lamp which permits the lamp to be turned horizontally and, at the same time, to be adjusted vertically through a wide range of angles.

It is a further object of the invention to provide an adapter of the type described which comprises relatively few parts, which is light in weight and of small dimensions and which may be manufactured at low cost.

In the accompanying drawing, Fig. l is a view showing the adapter mounting a lamp; Fig. 2

is a cross-sectional view through the device! Fig. 3 is a sectional view along the line 3-3 of Fig. 2; Fig. 4 is a view of the interior of the lamp receiving socket; Fig. 5 is a view showing the possible adjustment of the adapter from a vertical position; and Fig. 6 is a view showing the horizontal adjustment of the adapter.

Referring to the drawing, the adapter comprises generally an electric plug I0 adapted to be inserted in a plug receptacle and a receptacle ll adapted to receive the base of an electrical device, for example, an electric lamp. In Fig. 1, the adapter is shown supporting a projector lamp l2. Such lamps are frequently used in show case window lighting and must be adjusted through a wide range of angles to project a beam of light to any point in the. show case. This means that the lamp must be adjustable, both vertically and horizontally. To this end the receptacle H is so mounted on the plug base In that it may be tilted relative to the base l0 through a vertical angle of approximately 70, as shown by Fig. 5, and also through a horizontal angle of approximately 340, as shown by Fig. 6-. By this construction it is possible to provide a wide range of adjustment for a projection lamp simply by removing the lamp from its supporting shell. threading the plug base I0 into the shell and then mounting the lamp on the adjustable receptacle ll.

Turning now to the structure of the adapter, as shown in Figs. 2, 3 and 4, it will be seen that the plug I0 is formed with a base I3 having an integral extension M. The plug base is made of insulating material, for example, porcelain. Formed in the top of the base I3 is a recess IS the bottom of which merges with a channel l6 formed in the extension M. A supporting shell II, which is formed from a portion of a sphere,

is mounted within the recess IS with a part of the shell wall resting on the beveled edge I 8 of the recess. An opening I9 is formed in the shell at the point where it rests on the beveled edge I8 of the recess to provide a flange 20 which closely grips the Wall of the recess and prevents lateral displacement of the shell relative to the base I 0. When assembled in the manner indicated, the shell is free to rotate in a horizontal plane relative to the plug I0. Rotation for more than a complete revolution is prevented by engagement of a depending tang 2| formed on the shell I! with an abutment 22 upstanding from the wall of the recess.

The receptacle ll includes a supporting element 23 for a lamp socket provided with a center contact 24 and a threaded shell 25 forming another contact. The support 23 is made of any suitable insulating material, for example, a phenolic condensation product, and its outer surface is of spherical configuration in order that it may be seated within the spherical shell I! where it closely engages the inner surface of the shell for rotative movement therein. Each side of the spherical support 23 is provided with a trunnion 26 seated in bearings 21 cut in opposite sides of the edge 28 of the shell l1. There is a clearance of approximately between the trunnions and bearings so that the supporting element is frictionally seated within the shell and is merely guided in the bearings which prevent rotation in a horizontal plane relative to the shell. It should be noted that the edge 28 of the shell is formed at an angle of approxi mately 45 with the plug base l3. This means that the supporting element 23 may rotate within the shell through an angle of approximately without abutting against the edge of the shell. The range of movement is shown mostclearly by Fig. 5. The trunnion and bearing structure are in alignment with the central axis of the electric plug I!) so that when the support 23 is moved to the upright position shown by dotted lines in Fig. 5, the lamp base receiving shell 25 is in axial alignment with the electric plug l0.

The center contact 24 and the screw shell contact 25 are located within a recess 29 formed in one end of the supporting member 23. Conthe arms of which are compressed upon engagement with the center contact of a lamp base-threaded into the socket shell 26.

The center contact 24 is normally biased into engagement with a conducting member or arm 66 pivotally supported on a pin 66 the latter resting in a slot 61 i'orm'-d in the base of the recess. Upon tilting movement of the supporting member 26 the arm 66 moves in a groove 66, formed in the supporting member, and the arm pivots about the pin 66; angular movement 01 the supporting member is limited by engagement of the edge of the groove with the arm 66. The pin 66 and trunnions 26' are in substantially axial alignment so that when the supporting member 26 is moved to various angular positions it will pivot about an axis in line with both the trunnions 26 and the pin 66. This means that the conducting arm 66 maintains a fixed position at all times, this position being shown by Fig. 2. Theconducting arm is provided at one end with a substantially circular bearing surface 66' which maintains contact with the center contact 24 at all times irrespective of the positions to which the supporting member and center contact are moved. At the other end, the arm is formed with a flange 66 engaging a bushing 46 which, in turn, is threaded down upon one end of a coil spring 4|. The other end 0! the coil spring is connected to a nut 42 threaded on an adjustaable bolt 46. The bushing 40, spring 4|, and nut 42 are disposed within the channel i6 and surrounded bythe extension 4.

Mounted on the lower end of the plug extension i4 is a threaded shell 44 forming one contact element of the plug ID. The adjustable bolt 46 forms the other or center contact of the plug and for this purpose is provided with a head 46, The bolt 46 and the contact shell 44 are separated from one another by a disk 46 of insulating material for example, porcelain. The disk is of substantially circular configuration and bears against an inturned flange 41 of the shell 44 to hold it in position on the extension l4. The disk is provided with an opening 46 to receive the bolt 46. As shown more particularly by Figs. 2 and 3 the channel I6 is rectangular in cross-section and the disk 46 is provided with an upstanding boss 46 of corresponding rectangular form which fits in the end oi-the channel. This means that rotation of the disk 46 and contact shell 44 is prevented upon rotation of the adjusting bolt 46.

In order to connect electrically the plug shell 44 with the socket shell 26 an insulated conductor 66 is connected at one end to one of the bolts 62 holding the shell 26 in position, and at the other end is fastened to the intumed flange of the shell 44 at the point 6|. The conductor passes through an opening 62 formed in the wall of the extension l4 and thence to a groove 66 in the side wall of the extension where the connection 5| is made by any suitable means, such as solder or a weld. A sufllcient length of the conductor is provided to permit turning of the lamp receptacle without danger of damage or breakage of the conductor. To 'provide ample space in which the length of conductor may be coiled the supporting member 26 is provided with a recess 64.

In assembling the elements of the device the lamp receptacle contacts, the conducting arm 66, the spring 4| and the nut 42 are all mounted on the supporting member 26 which is then placed within the shell l1 and the assembly mounted inv the recess on the plug base l6. The

shell 44 and disk 46 are then placed on the extension and the adjusting bolt 46 is inserted through the opening 46 and threaded into the nut 42. Threading oi the bolt 46 in the nut 42 tensions the spring 4| and draws the supporting member 26 and shell down tightly upon the plug base. The pull of the spring is transmitted by the conducting arm 66 and pin 66 to the sup- Porting member 26. However. the spring is suiilciently resilient to permit angular movement of the supporting member 26 relative to the shell I! and to permit rotation of the shell about the plug base. The frictional force set up by the spring is sumcient to hold the supporting member and shell in whatever position they have been moved to. Adjustment of the frictional force isto be had by adjustment oi. the bolt 46.

In some cases it may be desirable to provide a locking means to maintain the supporting member 26 in the angular position to which it has been moved. To this end, a set screw 66 is placed in the shell I! and the end of the screw bears against the surface of the supporting member 26 to lock it in position. This structure is advantageous in those cases where the adapter may be subject to considerable vibration such that the supporting member may be jarred out oi position or where an exceptionally heavy lamp is placed in the lamp receptacle II. However, for most ordinary purposes the supporting member 26 is frictionally held in position by the spring 4| making the use of a locking screw unnecessary or, at best, a precautionary measure.

The spring 4lnot only assists in holding the elements of the adapter in assembled relationship but it also provides a conducting path for the current from the contact 46 oi the plug I6 to the center contact 24 of the receptacle I. Insertion of a lamp base in the receptable presses the contact 24 firmly into engagement with the circular bearing surface 65' on the conducting arm so that the arm is in conducting relationship with the contact irrespective oi the angular position to which the contact 24 and supporting member 26 have been moved. Upon rotation 01' the shell and supporting member about the base' i the shell i'l through more than a single revolution such as would tend to twist and damage the conductor is prevented by engagement of the tang 2| with the abutment 22.

While the invention has been illustrated and described with the shell "and the supporting member 26 having a spherical configuration, it should be manifest that the shape of these elements may be other than spherical so long as an angular adjustment between the two is provided for. The spherical configuration is advantageous, however, in that a smooth and effective frictional grip is obtained between the two members such that the lamp receptacle remains in the angular position to which it has been moved: moreover, this configuration makes possible a range of adjustment is ample for almost any use to which the lamp is to be put. When once adjusted to the selected position the adapter maintains the lamp in this position.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, an electric plug provided with electric contacts, a member rotatably mounted on said plug, a supporting element seated upon said rotatable member and adapted for angular movement relative to said member,

lamp receptacle contacts mounted on said supporting element, spring means interconnecting said supporting element and said electric plug for maintaining said rotatable member and said supporting element in position on said electric plug, said spring means forming an electrical conducting path between one of said plug contacts and one of said receptacle contacts, and electrical conducting means interconnecting the other of said plug and receptacle contacts.

'2. An adapter of the type described comprising an electric plug base having a recess therein, electrical contacts mounted on said plug base, a spherically shaped shell rotatably mounted within said recess, a supporting member of substantially spherical configuration seated within said shell and adapted for angular movement relative to said shell, lamp receptacle contacts mounted on said supporting member, an adjustable spring means interconnecting said supporting member and said plug base and adapted to hold said supporting member and said shell in assembled relationship on said base, said spring means forming an electrical conducting path between one of said plug contacts and one of said receptacle contacts, and electrical conducting means interconnecting the other of said plug and receptacle contacts.

3. An adapter comprising an electric plug provided with a base having a recess therein, 'contact members mounted on said base, a shell rotatably mounted within said recess, a supporting member seated within said shell and mounted for angular movement relative to said shell and base, receptacle contact means mounted on said supporting member and including a screw threaded shell and a central contact member, a conducting arm pivotally mounted within said supporting member and having an arcuate surface bearing against said center contact member, spring means connected at one end to said arm and at the other end to one of said plug contacts to form a conducting path between said 'plug contact and said central contact, said spring means normally biasing said conducting arm to hold the supporting member and shell in position on said base, and means electrically interconnecting said receptacle contact and the other of said plug contacts.

4. In combination, an electric plug having a recess therein, a spherically shaped shell rotatably mounted in said recess, a supporting member of substantially spherical configuration, said supporting member being provided with diametrically opposed bearing means for engaging the wall of said shell to support said member for annular movement within said shell, receptacle contacts mounted on said supporting member, and means electrically connecting said receptacle contacts with said electric plug.

5. In combination, an electric plug having a base provided with a recess therein, abutment means formed in said recess, electrical contacts mounted on said plug base, a shell rotatably mounted in the recess on said plug base, means projecting from said shell and adapted to engage said abutment means to prevent rotation of said shell beyond a predetermined position, a supporting member seated in said shell and being mounted for angular movement in a plane at right angles to that of rotation of said shell, receptacle contacts mounted on said supporting member, and means for electrically interconnecting said receptacle contacts and the contacts on said plug base.

6. An adapter comprising a plug base having a recess at one end andbeing provided with an extension at the other end, said extension being formed with a channel merging with said recess, a screw threaded shell mounted on the endof said extension and forming one plug contact, a rotatable bolt insulated from said shell and disposed within said channel to form the other of said plug contacts, a shell rotatably mounted in said recess, a supporting member seated within said shell and angularly movable in a plane at right angles to that of the plane of rotation of said shell, receptacle contacts mounted on said supporting member and comprising a screw shell and a centrally disposed spring contact member, a conducting arm "ivotally mounted within said supporting member and having a contact surface in engagement with said center receptacle contact, spring means disposed between said conducting arm and said adjustable bolt and being located in the channel in said extension, said spring means providing a conducting path from said adjustable bolt to said center contact and being adjustable on said bolt for holding the supporting member and shell in position on said plug base, and an insulated conductor interconnecting said plug and receptacle shells.

'7. In combination, an electric plug comprising a base having a recess therein, plug contacts mounted on said base including a threaded shell and a center contact, a supporting shell rotatably mounted within said recess, a supporting member pivotally mounted within said supporting shell and being adapted for angular movement relative to said shell in a plane substantially atright angles to that of rotation of said supporting shell, receptacle contacts mounted on said supporting member and including a threaded shell and a center contact, means electrically interconnecting the threaded shells of said plug and receptacle contacts, means electrically interconnecting the center contacts of said plug and receptacle including a conducting arm and spring, said spring maintaining said supporting member and shell in assembled relationship on said plug base, and means for locking said sup- :grting member and shell in angular relation- 8. An adapter comprising a plug base having a recess therein at one end and being provided with an extension at the other end, said extension being formed with a channel therein, a

spherically shaped shell rotatably mounted in the recess of said plug base, a supporting member pivotally mounted on said shell, receptacle contacts mounted on said supporting member, a conducting arm pivotally mounted on said supporting member and being in electrical engagement at one end with one of said receptacle contacts, the other end of said arm being formed with a flange, a bushing seated on said flange, a spring connected to said bushing and resting in the channel of said extension, an adjustable bolt forming a center plug contact and engaging the said spring to tension it and hold said supporting member and shell in assembled relationship on said base, and screw shell means forming the other of said plug contacts and being electrically connected to the other of said receptacle contacts. v

9. In combination, an electric plug having a recess therein, a spherically shaped shell rotatably mounted in said recess, a supporting member of substantially spherical configuration rotatably mounted within said shell for angular movement relative thereto, receptacle contacts mounted on said supporting member, and spring means cooperating with said electric plug and said supporting member and being biased to hold them together, and means for adjusting the biasing action of said spring.

10. In combination, a base provided with electric terminal members, a member rotatably mounted on said base, a supporting element seated upon said rotatable member and adapted for angular movement relative to said member, receptacle contacts mountedon said supporting element, spring means interconnecting said supporting element and said base for maintaining said rotatable member and said supporting element in position on said base, said spring means forming an electrical conducting path between one'of said base terminals and one of said receptacle contacts, and electrical conducting means interconnecting the other of said plug and receptacle contacts.

11. In combination, a base having a recess therein provided with electric terminal means, .a' metallic spherically shaped hollow shell rotatably mounted on said base, a supporting member of insulating material having a substantially spherical configuration, said supporting member being mounted within the hollowed portion of said shell for angular movement relative'thereto, receptacle contacts mounted on said supporting member, and means electrically connecting said receptacle contacts with said electric terminal means.

12. An adapter comprising an electric plug provided with a base having a recess therein, contact members mounted on said base, a shell rotatably mounted within said recess, a supporting member seated within said shell and being mounted for angular movement relative to said shell and base, receptacle contact means mounted on said supporting member and including a screw threaded shell and a central contact member, a conducting arm pivotally mounted within said supporting member and electrically connected to said center contact member, spring means connected at one end to said arm and at the other end to one of said plugs to form a conducting path between said plug contact and said central contact, said spring means normally biasing said conducting arm to hold the supporting member and shell positioned on said base, and means electrically interconnecting said threaded shell and the other of said plug contacts.

13. An adapter comprising a plug base having a recess at one end and being provided with an extension at the other end, said extension being formed with a channel merging with said recess, a screw threaded shell mounted on the end of said extension and forming one plug contact, an adjustable member insulated from said shell and disposed within said channel to form another plug contact, a. shell rotatably mounted in said recess, a supporting member seated within said shell and being angularly movable in a plane at right angles to that of the plane of rotation of said shell, receptacle contacts mounted on'said supporting member and comprising a screw shell and a centrally disposed contact member, a conducting arm pivotally mounted within said supporting member and electrically connected to said center receptacle .contact, spring means disposed between said conducting arm and said adjustable member, said spring means providing a conducting path 'fromsaid adjustable member to said center contact and being adjustable on said member for holding the supporting member and shell in position onsaid plug base.

14. In combination, an electric plug, a. spherically shaped shell rotatably mounted on said plug, a supporting member of substantially spherical configuration rotatably mounted within said shell forangular movement relative thereto, receptacle contacts mounted on said supporting member, and spring means cooperating with said electric plug and saidsupporting member and being placed under tension to hold said plug and member together for frictional movement relative to each other.

FRANK- c. DE REAMER. ARTHUR W. CLAUDER. 

